Wood Ear-like Co/FeLDHs@HNs Nanoheterojunction Drives PMS for Efficient and Rapid Degradation of Tetracycline

Environmental issues stemming from antibiotic misuse pose a significant threat to ecological security. The development of catalysts capable of activating peroxymonosulfate (PMS) and facilitating the generation of degradation-related free radicals remains a critical challenge. Herein, hydroxyapatite nanowires (HNs) were employed as carriers to synthesize a wood ear-like heterojunction (Co/FeLDHs@HNs) via in situ integration of Co/Fe layered double hydroxides (Co/FeLDHs) on the HNs surface. The Co/FeLDHs@HNs combined with PMS (Co/FeLDHs@HNs/PMS) generates substantial reactive oxygen species (ROS), including singlet oxygen (¹O₂), sulfate radicals (SO₄^•-), hydroxyl radicals (^•OH), and superoxide radicals (^•O₂^-), which collectively contribute over 90% to the degradation of tetracycline hydrochloride (TCs), achieving a removal rate of 98% within 5 min. This high efficiency is primarily attributed to the continuous generation of ROS as the dominant active species in pollutant degradation, with the heterojunction structure facilitating electron transfer and PMS activation to sustain ROS production throughout the process. Additionally, the unique wood ear-like morphology, characterized by its high aspect ratio and hierarchical porous structure, increases the surface area and exposure of active sites, facilitating mass transfer and accelerating interfacial electron interactions, thereby enhancing catalytic performance. This system also demonstrates excellent reusability, maintaining around 83% efficiency after eight cycles, and displays low biotoxicity with potential for agricultural applications. This work provides valuable insights into designing advanced catalysts for effective environmental remediation.